'''
Function:
    stackoverflow模拟登录
        --PC端: https://stackoverflow.com/
        --移动端暂不支持
Author:
    Charles
微信公众号:
    Charles的皮卡丘
GitHub:
    https://github.com/CharlesPikachu
更新日期:
    2020-03-12
'''
import re
import requests


'''
Function:
    stackoverflow模拟登录
Detail:
    -login:
        Input:
            --username: 用户名
            --password: 密码
            --mode: mobile/pc
            --crackvcFunc: 若提供验证码接口, 则利用该接口来实现验证码的自动识别
            --proxies: 为requests.Session()设置代理
        Return:
            --infos_return: 用户名等信息
            --session: 登录后的requests.Session()
'''
class stackoverflow():
    def __init__(self, **kwargs):
        self.info = 'stackoverflow'
        self.session = requests.Session()
    '''登录函数'''
    def login(self, username, password, mode='pc', crackvcFunc=None, **kwargs):
        # 设置代理
        self.session.proxies.update(kwargs.get('proxies', {}))
        # 移动端接口
        if mode == 'mobile':
            raise NotImplementedError
        # PC端接口
        elif mode == 'pc':
            self.__initializePC()
            # 获得fkey
            fkey = self.__getFkey()
            # 模拟登录
            data = {
                    'openid_identifier': '',
                    'password': password,
                    'fkey': fkey,
                    'email': username,
                    'oauth_server': '',
                    'oauth_version': '',
                    'openid_username': '',
                    'ssrc': 'head'
                }
            params = {
                    'ssrc': 'head',
                    'returnurl': 'https://stackoverflow.com/'
                }
            res = self.session.post(self.login_url, data=data, params=params)
            # 登录成功
            if res.history:
                res = self.session.get(self.home_url)
                profile_url = 'https://stackoverflow.com' + re.findall(r'<a href="(.+)" class="my-profile', res.text)[0]
                print('[INFO]: Account -> %s, login successfully...' % username)
                infos_return = {'username': username, 'fkey': fkey, 'profile_url': profile_url}
                return infos_return, self.session
            # 登录失败
            else:
                raise RuntimeError('Account -> %s, fail to login, username or password error...' % username)
        # mode输入有误
        else:
            raise ValueError('Unsupport argument in stackoverflow.login -> mode %s, expect <mobile> or <pc>...' % mode)
    '''获得fkey值'''
    def __getFkey(self):
        params = {
                    'ssrc': 'head',
                    'returnurl': 'https://stackoverflow.com/'
                }
        res = self.session.get(self.login_url, params=params)
        fkey = re.findall(r'"fkey":"([^"]+)"', res.text)[0]
        return fkey
    '''初始化PC端'''
    def __initializePC(self):
        self.headers = {
                        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36',
                        'Content-Type': 'application/x-www-form-urlencoded;charset=utf-8'
                    }
        self.login_url = 'https://stackoverflow.com/users/login'
        self.home_url = 'https://stackoverflow.com/'
        self.session.headers.update(self.headers)
    '''初始化移动端'''
    def __initializeMobile(self):
        pass


'''test'''
if __name__ == '__main__':
    stackoverflow().login('', '')